Enable common subexpression optimization in GCC. * lib/unitypes.in.h (_UC_ATTRIBUTE_CONST, _UC_ATTRIBUTE_PURE): New macros. * lib/unicase.in.h (uc_toupper, uc_tolower, uc_totitle): Declare with GCC attribute 'const'. (uc_locale_language): Declare with GCC attribute 'pure'. * lib/unicase/caseprop.h (uc_is_cased, uc_is_case_ignorable): Declare with GCC attribute 'const'. * lib/unictype.in.h (uc_is_general_category_withtable, uc_combining_class, uc_combining_class_name, uc_combining_class_long_name, uc_bidi_class_name, uc_bidi_category_name, uc_bidi_class_long_name, uc_bidi_class, uc_bidi_category, uc_is_bidi_class, uc_is_bidi_category, uc_decimal_value, uc_digit_value, uc_numeric_value, uc_joining_type_name, uc_joining_type_long_name, uc_joining_type, uc_joining_group_name, uc_joining_group, uc_is_property_*, uc_script, uc_block, uc_is_c_whitespace, uc_is_java_whitespace, uc_c_ident_category, uc_java_ident_category, uc_is_alnum, uc_is_alpha, uc_is_cntrl, uc_is_digit, uc_is_graph, uc_is_lower, uc_is_print, uc_is_punct, uc_is_space, uc_is_upper, uc_is_xdigit, uc_is_blank): Declare with GCC attribute 'const'. (uc_general_category_name, uc_general_category_long_name, uc_general_category_byname, uc_general_category, uc_is_general_category, uc_combining_class_byname, uc_bidi_class_byname, uc_bidi_category_byname, uc_joining_type_byname, uc_joining_group_byname, uc_script_byname, uc_is_script, uc_is_block): Declare with GCC attribute 'pure'. * lib/unigbrk.in.h (uc_graphemeclusterbreak_property, uc_is_grapheme_break, u8_grapheme_next, u16_grapheme_next, u32_grapheme_next, u8_grapheme_prev, u16_grapheme_prev, u32_grapheme_prev, lib/uniname.in.h (unicode_name_character): Declare with GCC attribute 'pure'. * lib/uninorm.in.h (uc_composition): Declare with GCC attribute 'const'. (uninorm_decomposing_form): Declare with GCC attribute 'pure'. * lib/unistr.in.h (): Declare with GCC attribute 'const'. (u8_check, u16_check, u32_check, u8_mblen, u16_mblen, u32_mblen, u8_cmp, u16_cmp, u32_cmp, u8_cmp2, u16_cmp2, u32_cmp2, u8_chr, u16_chr, u32_chr, u8_mbsnlen, u16_mbsnlen, u32_mbsnlen, u8_strmblen, u16_strmblen, u32_strmblen, u8_strlen, u16_strlen, u32_strlen, u8_strnlen, u16_strnlen, u32_strnlen, u8_strcmp_gnu, u8_strcmp, u16_strcmp, u32_strcmp, u8_strncmp, u16_strncmp, u32_strncmp, u8_strchr, u16_strchr, u32_strchr, u8_strrchr, u16_strrchr, u32_strrchr, u8_strcspn, u16_strcspn, u32_strcspn, u8_strspn, u16_strspn, u32_strspn, u8_strpbrk, u16_strpbrk, u32_strpbrk, u8_strstr, u16_strstr, u32_strstr, u8_startswith, u16_startswith, u32_startswith, u8_endswith, u16_endswith, u32_endswith): Declare with GCC attribute 'pure'. * lib/uniwbrk.in.h (uc_wordbreak_property): Declare with GCC attribute 'const'. * lib/uniwidth.in.h (uc_width): Simplify declaration. (u8_width, u16_width, u32_width, u8_strwidth, u16_strwidth, u32_strwidth): Declare with GCC attribute 'pure'.

--- a/lib/unitypes.in.h
+++ b/lib/unitypes.in.h
@@ -1,4 +1,4 @@
-/* Elementary types for the GNU UniString library.
+/* Elementary types and macros for the GNU UniString library.
    Copyright (C) 2002, 2005-2006, 2009-2012 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify it
@@ -23,4 +23,24 @@
 /* Type representing a Unicode character.  */
 typedef uint32_t ucs4_t;
 
+/* Attribute of a function whose result depends only on the arguments
+   (not pointers!) and which has no side effects.  */
+#ifndef _UC_ATTRIBUTE_CONST
+# if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+#  define _UC_ATTRIBUTE_CONST __attribute__ ((__const__))
+# else
+#  define _UC_ATTRIBUTE_CONST
+# endif
+#endif
+
+/* Attribute of a function whose result depends only on the arguments
+   (possibly pointers) and global memory, and which has no side effects.  */
+#ifndef _UC_ATTRIBUTE_PURE
+# if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+#  define _UC_ATTRIBUTE_PURE __attribute__ ((__pure__))
+# else
+#  define _UC_ATTRIBUTE_PURE
+# endif
+#endif
+
 #endif /* _UNITYPES_H */